This invention relates to the use of salts of low molecular weight polymers of methacrylic and acrylic esters as sole vehicles for the formulation of aqueous, high gloss, essentially water clear finishes with autoredispersible properties. For example, the polymers are used in aqueous polishes for solid substrates such as floors, walls, furniture, doors, trim and appliances. The substrates may be bare, e.g., bare metal, wood, plastic, mineral such as stone, brick, concrete or other composite including vinyl, rubber and asbestos tile, or the substrates may be painted, varnished, lacquered, papered or coated by other materials producing a hard surface. These low molecular weight polymers, also known as oligomers, are particularly well adapted to the formulation of a wide variety of autoredispersible finishes which on application and drying form clear coatings having a glossy appearance. Illustrative of the variety are (1) water resistant, detergent sensitive household floor polishes, (2) water resistant, detergent resistant industrial floor polishes, and (3) hard surface cleanser and polish for use on all wall surfaces.
It is known to employ as protective coatings, particularly as floor coatings, compositions containing aqueous polymeric dispersions of water-insoluble emulsion copolymers, as the vehicle, in admixture with a wax, an alkali-soluble resin, wetting, emulsifying and dispersing agents, and a polyvalent metal compound. The water-insoluble emulsion copolymers, which are used as the vehicle in these coatings, are high in molecular weight by their nature. These polish compositions have a particularly advantageous balance of properties, including high gloss coupled with detergent resistance, recoatability and good removability.
Other conventional polishes continue to build up on reapplication to the floor or other solid substrate and ultimately require a laborious, objectionable stripping operation to restore a uniformly clean floor. The polish films based on products from this invention are selfdispersible. During polish reapplication, the previous film is dissolved and the embedded soil removed, leaving a film which on drying is comparable in thickness to the original film. Thus, without film buildup, the three separate steps normally involved in maintenance are accomplished (cleaning, stripping previous coats of polish and repolishing) in a single step.
The hard surface cleaner-polish of this invention differs from conventional all-purpose cleaners in leaving a film on the cleaned surface. This film restores the luster of the surface and seals it, making the substrate more resistant to new soil. The film, formed on drying, is soluble and dispersible in fresh cleaner-polish, so on recleaning, the old film dissolves, releasing accumulated soil. Use of the cleaner-polish thus results in less scrubbing effort in cleaning as well as reducing the wear and damage to the substrate by facilitating the removal of oily and greasy soils, particulate dirt, water-soluble matter and other types of household soils.
Other polymers of relatively low molecular weight and aqueous alkali solubility, such as rosin acid adducts, styrene/acrylic acid, and styrene/maleic anhydride resins, are found to impart good leveling and flow properties to polishes containing higher molecular weight polymeric vehicles but are unsatisfactory when used solely as the major polymeric constituent in aqueous soluble floor polishes. Their defects include: unacceptable low water resistance, unsatisfactory recoatability, poor wear properties, and poor initial color and color stability. Although the addition of low levels of polyvalent metal ions (e.g., Zn) may be used to improve these properties, it does so at the expense of gloss, so polishes based on those other polymers remain inferior to polishes of the polymers disclosed herein.